Transmission for automobiles.



W/ T/vEss A. W. GROTE.

TRANSMISSION FOR AUTOMOBILES.

APPLICATION FILED JUNE 30. I9l7.

Patented May 7,1918.

2 SHEETS-SHEET I.

INVENTOR A TTORNEYS A. W. GROTE.

TRANSMISSION FOR AUTOMOBILES.

APPLICATION FILED JUNE 30. I917.

1,265,07 8. Patented May 7,1918.

2 SHEETSSHEET 2.

lNVL-WTOI? I I @WMM T Ess; a a I A TTORA/EYS ALFRED w. GBOTE, OF BROOKLYN, NEW YORK.

TRANSMISSION FOB AUTOMOBILES.

Specification of Letters latent.

Patented May '7, 1918.

Application flied June 30, 1917. Serial No. 177,951.

To all whom it may concern:

Be it known that I, ALFRED W. Gno'rn, a citizen of the United States, resldlng 1n the borough of Brooklyn of the city of N ew York, in the State of New York, have mvented certain new and useful Improvements in Transmissions for Automobiles, of which the following is a specification, reference being had to the accompanying drawings, forming a part hereof.

This invention relates to a combined magnetic and mechanical transmission for automobiles in which the objectionable features of magnetic and mechanical transmissions alone are eliminated and the desirable features thereof are retained and combined in such manner as to insure a flexible drive at different speeds and a simple control. In accordance with the invention the usual sets of gears for giving the diflerent speed ratios are retained, but these sets of gears instead of being slidable under the control of the operator as by means of mechanical or electrical devices remain always in mesh, respectively, so that the inconvenience and liability to damage constantly present with shiftable gears are overcome. The several transmission gears are provided with separate magnetic drives, the control of which is placed selectively in the hands of the operator. By providing separate magnetic drives non frictional for the respective speed gears, reliance is placed on only one of such drives for each different speed, so that derangement of any one drive will not affect the operation of th remaining drives. In this way, the objectionable features of the usual single unit magnetic drive are eliminated and the required flexibility is retained. The combining of the magnetic drives, 0 erating through magnetic drag, without rictional contact, with the mechanical speed reduction through gears constitutes the most important advance made by the present invention. Reference is to be had to the accompanying drawings for a detail description of one illustrative embodiment of the invention, in which- Figure 1 is a view in section taken through the revolving cage of the magnetic units and the gear housing.

Fig. 2 is a view partly in section and partly in elevation, taken along the plane indicated by the broken lines 22 of Fig. 1 and looking in the direction of the arrows.

Fig. 3 is a schematic view of the electrical controlling system for the magnetic drives.

The motor shaft a may carry thereon the usual flywheel 7) to the face of which may be secured a revolving cage or housing a for the elements of the magnetic drive. This cage 0 carries in its peripheral wall several pairs of pole pieces d, e, f, the poles of each pair being diametrically opposed, and for compactness and convenience in construction, some pairs of which may be set at 90 from other pairs. In the illustrated embodiment there are shown four such pairs of pole pieces, since that number will be required for a transmission in which there are three speeds forward and reverse. Each pole piece may be laminated, as usual, and provided with an energizing or field coil g, these poles being mounted for accessibility on the outer peripheral wall of the cage 0. The pairs of respective coils, as indicated schematically in Fig. 3, are connected re spectively to contact rings h, mounted on the end wall of the cage 0. Operatively mounted with relation to each one of these rings is a brush 2' connected to a suitable source of current and a switch or other controlling device 71 whereby current may be led to any one of the pairs of field coils de pending upon which one the operator desires to energize for control of the car in a manner which will appear.

Extending through the end wall of the cage 0 and journaled therein by any suitable bearings are several shafts, the inner one is of which may be solid while the outer ones Z, m, n, are tubular to receive rotatably the shaft disposed therein. These shafts are of diiferent lengths, as appears particularly from Fig. 1, and on the ends of each one within the cage 0 is mounted an armature k Z, m and 11., respectively. These armatures are of suitable form and dimensions and extend diametrically through the cage between the respective pairs of pole pieces, the outer end of each armature conforming to the shape of the face of each pole piece, so that there will be left between the armatures and the pole pieces air gaps of about the usual width provided in machines of this character. The other ends of the several shafts 7:, Z, m, n, extend into a gear casing 0 and terminate at difl'erent points within the gear casing, so as to carry on such ends speed gears 70 Z m, if, respectively,

these gears being of any predetermined diameter according to the speed ratios desired. Within the gear casing 0 is also journaled a separate shaft p which may be coupled with the usual propeller shaft, and on the shaft p are mounted to mesh with the respective gears on the shafts Z, m, a, speed gears Z m 11;, respectively. The gear k on the fourth shaft may mesh with an idler 70 mounted in the gear case 0 and this idler may, in turn, mesh with the gear is on the shaft 10, the introduction of the idler 70 in this train, giving the desired reverse.

The transmission just described partakes in placed. The fly-wheel b with the cage a revolves constantly by reason of its direct connection to the motor shaft a. So long as the controlling devices for the several circuits in which are included the rings z' are open, the circuits will remain open and the cage 0 will revolve idly. When the operator desires to start the car, for instance, he moves the appropriate controlling device, whether it be a push button or lever, so as to energize one of the pairs of coils g and thereby set up a magnetic drag on the proper armature, say, the armature Z for lowest speed without frictional contact between the driving part and the driven part. Rotation of the armature Z with its shaft Z and gear Z is, of course, transmitted to the driving shaft 1) through the gear Z all of the other fields g at thls time being de'elnergized and the remaining gears revolving idly. When suflicient momentum has been acquired and it is desired to change to a higher speed the coils g for the armature Z will be cut out and the coils for, say, the armature 111/, will be energized by proper manipulation of the controlling devices or their circuit, so that the drive of the motor will be taken magnetically through the shaft m to the gears m m For high speed, the operator will cut out the last named coils and energize the coils for the armature n so as to obtain the high speed ratio given by the gears n n. For reverse, the coils for the armature 70 will be energized and reverse drive obtained through the idler k in a manner which will be evident.

From the foregoing description, it w1ll be evident that the speed variations are obtained primarily through change speed gears arranged in sets of different ratios in a manner commonly employed, but these several sets of gears remain constantly in mesh so that the inconvenience attached to their constant shifting, as is usual in mechanical transmissions, is eliminated. Further, the objectionable mechanical features incidental to mechanical gear shifting devices are overcome. The gears remain in constant mesh and run noiselessly and give the desired speed Variations in a positive manner. The magnetic drive obtained with the several units described is flexible, but since separate drives are provided for the separate speeds, the derangement of any one drive will not prevent operation of the car through the remaining drives. quite evident, for instance, that were the low speed magnetic drive out of commission for some reason, the car might be started slowly on second speed or, indeed, on high speed. If desirable, it will be evident to.

the skilled mechanic that resistances for the diflerent circuits might be introduced and these reistances made controllable, so that for each one of the magnetic driving units provided, a limited variation of the flux and consequent slippage might be obtained suflicient to give a limited variation of speed and power, which would insure that absolute flexibility which would best protect the magnetic elements in the transmission. It will be observed that the transmission of power between the rotatable magnetic fields and the armatures without contact of metal to metal, avoids the objections to the use of frictional clutches and at the same time affords greater elasticity in speed variation.

Changes in the precise form of the elements described may be made without departing from the spirit of the invention, which, as noted before, resides primarily in the combining of a magnetic clutch operating solely through magnetic drag without frictional contact between the members and mechanical transmission in such manner as to overcome the objections now common to each of these transmission when used alone.

I claim as my invention:

1. A transmission comprising a driving shaft, a driven shaft, speed gears in constant mesh interposed operatively between said shafts, magnetic devices operatively interposed between said driving shaft and the driving gears and comprisin a magnetic field and an armature for eac speed gear, the one carried with the driving shaft and It will be the other with the gear, with an air gap beeach of said last named shafts, magnetic devices cooperating with said armatures to couple them magnetically with the driving shaft and means to control the magnetic devices selectively.

3. A transmission comprising a driving shaft, a driven shaft, speed gears in constant mesh interposed operatively between said shafts, separate shafts on which the driving gears are mounted, armatures on each of said. last named shafts, magnetic field pieces carried with the driving shaft and cooperating with said armatures to couple them magnetically with the driving shaft and means to operate the magnetic devices selectively.

4. A transmission for automobiles comprising a driving shaft, a driven shaft, speed gears in constant mesh interposed operatively between said shafts, separate shafts on which the driving gears are mounted, armatures on each of said last named shafts, a circular cage carried with the driving shaft, pole pieces mounted in the peripheral wall of the cage to cooperate respectively with the armatures, fields for said pole pieces and means to energize the fields selectively for coupling the various fields magnetically with the respective armatures.

5. A transmission for automobiles comprising a driving shaft, a driven shaft, speed gears of different ratios in constant mesh interposed operatively between said shafts, tubular shafts of different lengths mounted one within another on which the driving gears are carried, armatures on each of said last named shafts, a circular casin carried with the driving shaft and provi ed with magnetic field pieces cooperating With said armatures to couple them magnetically with the driving shaft, and means to control the magnetic devices selectively.

6. A transmission for automobiles comprising a driving shaft, a driven shaft, speed gears in constant mesh interposed o eratively between said shafts, separate shaf ts on which the drivin gears are mounted, armatures on each 0 said last named shafts, a

circular casing carried with the driving shaft, magnetic field pieces mounted in the peripheral wall of the casing, contact rings for the fields of the respective armatures carried on the casing, brushes cooperating with the contact rings and means to control the circuits of the fields selectively.

'7. A transmission for automobiles comprising a flatwheel mounted thereon, a driven shaft, speed ears in constant mesh interposed operative y between said shafts, separate shafts on which the driving gears are mounted, armatures on each of said last named shafts, a circular casing mounted on the face of the flat wheel and inclosin said armatures, bearings in the end wall 0 said casing for said last named shafts, magnetic field pieces mounted in the peripheral wall of the casing for cooperation with the respective armatures and means to control the magnetic devices selectively to couple them magnetically with the driving shaft.

8. A transmission for automobiles comprising a driving shaft, a driven shaft, speed gears of difierent ratios in constant mesh interposed operatively between said shafts, a

gear casin inclosing said gears, telescoped separate s afts on which the drivin gears are mounted journaled in the end wal of the gear casing, armatures on each of said last named shafts, a circular casing for the armature carried with the driving shaft, said tubular shafts extending through the end wall of the circular casin and being journaled therein magnetica l field pieces mounted in the peripheral wall of the circular casing and cooperating with the armatures, field windings for the field pieces carried on the outer peripheral wall of the circular casing, contact rings for the respective field windings on the end wall of the circular casing, brushes cooperating with the rings and means to control the several cir-'" cuits selectively.

This specification signed this 25th day of June A. D. 1917.

ALFRED W. GROTE. 

